Sentences with phrase «ozone levels by»

The detailed study shows that Americans face the risk of a 70 percent increase in unhealthy summertime ozone levels by 2050.

City of Dallas Texas Government 334 million green kWh, 40 % of total power used After hosting an eye - opening climate conference, the city government decided to help lower statewide ozone levels by decreasing its conventional power use, says Jill Jordan, an assistant city manager.

«Ozone recovery may be delayed by unregulated chemicals: Recent increases in an unregulated ozone - depleting substance, could delay recovery of Antarctic ozone levels by 5 - 30 years, depending on emissions scenarios.»

Recent increases in an unregulated ozone - depleting substance, could delay recovery of Antarctic ozone levels by 5 - 30 years, depending on emissions scenarios.

Not exact matches

State Attorney General Eric Schneiderman said he would sue the EPA over what he said was the agency missing a statutory deadline for designating areas of the country impacted by unhealthy levels of ground - level ozone.

State AG Eric Schneiderman, leading a coalition of 15 state attorneys general, today filed a lawsuit against the EPA and its administrator, Scott Pruitt, for failing to meet the Clean Air Act's statutory deadline for designating areas of the country impacted by unhealthy levels of ground - level ozone (commonly referred to as smog).

If Lu's suggestion is correct, ozone levels should fall then rise every 11 years, in step with changes in cosmic - ray intensity driven by the 11 - year solar cycle.

The region's levels of ozone and particulate matter, two pollutants caused by both automobiles and industry, exceed national air quality standards.

Regulations on VOCs vary by state, but most consumer products are regulated only for their potential contribution to ground - level ozone, not fine particulate matter.

Without the Montreal Protocol and associated agreements, atmospheric levels of ozone depleting substances could have increased tenfold by 2050.

In this study in Timothy grass, researchers led by environmental health scientist Christine Rogers of the UMass Amherst School of Public Health and Health Sciences (SPHHS) determined the interactive effects of CO2 and ozone at projected higher levels on pollen production and concentrations of a Timothy grass pollen protein that is a major human allergen.

They found that elevated CO2 of 800 ppm, increased pollen production per flower by 53 percent while the different ozone levels had no effect on the amount of pollen produced.

Its contribution to heating forcing (caused by greenhouse gases, ground - level ozone and «black carbon» [4]-RRB- is 12 % on average.

Solomon and her colleagues believed they would get a clearer picture of chlorine's effects by looking earlier in the year, at ozone levels in September, when cold winter temperatures still prevail and the ozone hole is opening up.

As chlorine levels continue to dissipate from the atmosphere, Solomon sees no reason why, barring future volcanic eruptions, the ozone hole shouldn't shrink and eventually close permanently by midcentury.

A new computer simulation suggests that the water vapour and sea salt thrown up by the impact could damage the Earth's protective ozone layer, leading to record levels of ultraviolet radiation that could threaten human civilisation.

Using a computer model that fused air pollution and atmospheric chemistry data, they estimated what annual average levels of ozone (a key smog ingredient) and fine particulates smaller than 2.5 microns (PM2.5) were in 2010 within 100 - km - by -100-km grid squares across the world.

But ground - level ozone — the chemical combustion product of factory and vehicle emissions heated by sunlight — can have a devastating effect.

Air monitoring by researchers in 2000 found levels of volatile organic compounds — highly reactive ozone precursors such as benzene, known as VOCs — were 10 to 100 times higher than what had previously been estimated.

The formation of large areas of high pressure in the lower atmosphere both lowers ozone levels, by squeezing the ozone layer above, and may provide the very cold conditions in which ozone destruction is greatest.

Similarly, if the level of ozone could be lowered by just 1 part per billion (ppb) nationwide, about 1,900 lives would be saved each year.

A new study of 60 million Americans — about 97 % of people age 65 and older in the United States — shows that long - term exposure to airborne fine particulate matter (PM2.5) and ozone increases the risk of premature death, even when that exposure is at levels below the National Ambient Air Quality Standards (NAAQS) currently established by the U.S. Environmental Protection Agency.

A final possibility is that there has been increased formation of the hydroxyl radical in the atmosphere — perhaps caused by the thinning of the ozone layer, which allows more ultraviolet radiation to reach low levels.

Within 24 hours of the blackout, sulfur dioxide levels dropped by 90 percent, and ozone declined by 50 percent.

Shown are the 1988 - 2014trends in springtime ozone levels on days that were very smoggy (top panel) and of average smogginess (bottom panel), from observations (left) and from a model built by the Geophysical Fluid Dynamics Laboratory (right).

Ozone levels have increased in the west, as indicated by the red circles, despite a 50 percent reduction in the emission of smog - forming pollutants.

On very smoggy days (top panel), ozone levels have declined in the east, as indicated by the blue circles.

The researchers estimate that cutting those 14 together could avoid between 700,000 and 4.7 million premature deaths (largely from smoky, unhealthy air) and increase crop yields by between 30 million and 135 million metric tons (due to concomitant reductions in ground - level ozone, otherwise known as smog, which forms from fugitive methane and blights crops in Brazil, China, India, the U.S. and elsewhere).

Unlike Newchurch, Harris thinks ozone depletion is now reaching a plateau and will soon start recovering: «Ozone should be at pre-1980 levels by 2020.&rozone depletion is now reaching a plateau and will soon start recovering: «Ozone should be at pre-1980 levels by 2020.&rOzone should be at pre-1980 levels by 2020.»

A Northwestern University study by an economist and a chemist reports that when fuel prices drove residents of São Paulo, Brazil, to mostly switch from ethanol to gasoline in their flexible - fuel vehicles, local ozone levels dropped 20 percent.

Unlike ozone in the stratosphere, which benefits life on Earth by blocking ultraviolet radiation from the Sun, ground - level ozone can trigger a number of health problems.

According to data from the U.S. Environmental Protection Agency (EPA), levels of all major air pollution contaminants (ozone, nitrogen oxides, carbon monoxide, sulfur dioxide, particulate matter and lead) are down significantly since 1970; carbon monoxide levels alone dropped by more than 70 percent.

A 20 - year study by German scientists has found that the rate of increase of CFC - 12, a chlorofluorocarbon compound that spawns ozone - destroying reactions in the stratosphere, has slowed since 1990, although absolute levels are still rising.

But the researchers, led by AWI atmospheric scientist Markus Rex, found levels in the west Pacific below 10 ozone particles per billion — so low their instruments couldn't even get a precise count.

The report lists 30 cities that face increased health risks from heat waves worsened by global warming, based on a combination of four factors: average number of summer days with «oppressive» summer heat, the percentage of households without central air conditioning, ground - level ozone levels, and the percentage of households below the poverty line.

Climate change is projected to harm human health by increasing ground - level ozone and / or particulate matter air pollution in some locations.

As a result of regulation by the Montreal Protocol, the levels of ozone - depleting chlorine and bromine stopped growing in the atmosphere in the mid-1990s, and have been decreasing at nearly the expected rate.

These can have a limited effect on ozone levels (by serving as hetrogeneous reaction sites) and can reflect enough of the sun's light back into space to cause a notable global cooling.

«In some sense, we might have competing effects going on in Antarctica where there is low - level CO2 warming but that may be swamped by the effects of ozone depletion,» he said.

The study — complete details of which have been published in the journal Nature Geoscience — further revealed that the ozone levels in the atmospheric troposphere above China have increased by 7 percent between 2005 and 2010.

For soybeans, the researchers found that 46 percent of damage was actually caused by increased ozone levels — and not by increased heat, as had been previously thought.

Ozone should recover to its pre-1980 levels by the middle of this century and slightly later for Antarctica where the protective gas layer gets extremely thin between August and December every year, the WMO reportedly said, adding that the process can be speeded up by almost 11 years if existing stocks of ozone - depleting products, such as those found in old refrigerators and fire extinguishers are destrOzone should recover to its pre-1980 levels by the middle of this century and slightly later for Antarctica where the protective gas layer gets extremely thin between August and December every year, the WMO reportedly said, adding that the process can be speeded up by almost 11 years if existing stocks of ozone - depleting products, such as those found in old refrigerators and fire extinguishers are destrozone - depleting products, such as those found in old refrigerators and fire extinguishers are destroyed.

Increased incidence of cardio - respiratory diseases caused by higher concentrations of ground - level ozone (smog) is projected.

In addition, ground - level ozone (O3) and secondary particulate matter are often referred to among the CAC because they both are by - products of chemical reactions between the CACs that take place in the atmosphere.

Early Earth lacked an ozone layer to act as a shield against high - energy solar radiation, but microbes flourished by adapting to or finding other forms of protection from the higher ultraviolet radiation levels.

When ozone exposure decreased by 10 parts per billion — and was at a level well below the federal air quality standard — the workers were 5.5 percent more productive.

Federoff's team is studying Arabidopsis to find out which genes are turned on or off by different levels of ozone.

Fine particles emitted by vehicles (especially diesel - powered ones), coal - fired power plants, and burning wood can penetrate deep into the lungs, while car exhaust, heat, and sunlight contribute to high ozone levels.

Cities earn up to two additional points for air quality, as measured by the amount of ground - level ozone and particulate matter its residents are forced to breathe.

The bulk of the ozone is at lower levels and is not affected by the processes decribed by Randall et al..